Adjustable valve gear for steam engines



June 4, 1940. R. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM mamas l1 Sheets-Sheet 1 Filed July 13, 1958 June 4, 1940. R. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Filed July 13, 1938 ll Sheets-Sheet 2 #Ma ATTORNEYS INVENTOR Nnm NmN

Q Q Q June 4, 1940. R. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM ENG INES 11 Sheets-Sheet 5 Filed July 13, -193a INVENTOR Wm M BY j v v ATTORNEY! June 4, 1940. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM ENGINES ll Sheets-Sheet 4 Fileq ,July 15, 1938 INVENTOR A g I JQI LYyQW ATTORNEYJ June 4, 1940. R. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Filed July 13, 1938 ll Sheets-Sheet 5 INVENTOR M M 4464, ATTORNEYS R. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Filed July 13, 1958 11 Sheets-Sheet 6 lN VENTOR BY W1 MW ATTORNEY! June 4, 1940. R. R. BUSH 3,

. ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Filed July 13, 1938 11 Sheets-Sheet 7 INVENTOR BYWMM ATTORN EU June 4, 1940. R. R. BUSH ADJUSTABLE VALVE mm FOR swam ENGINES F'iied July 15, 1938 11 Sheets-Sheet a INVENTOR BY #Mw! ATTORNEY$ June 4, 1940. R, R, BUSH A 2,203,379

ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Filed July 13, 1938 ll Sheets-Sheet 9 INN 7/ A. 1 x J; X 2

' INVENTOR J fmm M June 4, 1940. R. R. BUSH ADJUSTABLE VALVE GEAR FOR STEAM ENGINES 11 Sheets-Sheet 1O INVENTOR Wm M Filed July 13, 1938 ATTORNEYJ' June 4, 1940. R, R, BUSH 2,203,379

ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Filed July 15, 1938 11 Sheefs-Sheet 11 INVENTOR WWW E ATTORNEYJ Patented June 4, 1940 UNITE!) srres P TET ADJUSTABLE VALVE GEAR FOR STEAM ENGINES Application July 13, 1938, Serial No. 219,070

22 Claims.

This invention relates to adjustable valve gear For steam engines, and more particularly to locomotive valvegear of the adjustable and reversible type.

Although in its broader aspects the valve gear -:f the present invention is adaptable to operate variety of types of steam distribution valves in locomotives and is adapted to be actuated from various of the reciprocating and/or rotating parts of the locomotive running gear, yet the invention is especially advantageous when employed in association with poppet valves and when actuated from the cross-heads at the .two sides of the locomotive engine, and it will therefore be described herein with reference to such an installation. For a fuller disclosure of this field of application, reference may be made to certain copending applications of William E. Woodard, which may be briefly mentioned as .follows:

In application 53,504, filed January 10, 1936, which issued November 15, 1938, as Patent 2,- 136,405, there is disclosed a valve motion'mechanisni centrally disposed between the cylinders and adapted to variably and reversibly combine motions derived from the crossheads at the two sides of the locomotive engine and to utilize the combined motion for actuating admission poppet valves and exhaust poppet valves for both cylin so ders of the locomotive.

In application 121,398, filed January 21, 1937, which issued November 29, 1938, as Patent 2,- 138,053, there is disclosed a valve motion mechanism for locomotive engines, wherein the motions of a plurality of actuating parts are combined in one ratio for the timing of the admission valves and in a different ratio for the timing of the exhaust valves, whereby an improvement in the valve events is effected, notably a m delaying of the release and compression events as compared with previous practice, particular" 1y when the valve gear is adjusted to efiect early cut-oil.

In application 217,360, filed July .5, 1938, there to is disclosed a valve motion mechanism for fluid pressure engines wherein a further improvement of the timing of the valves is secured, particularly by efiecting an adjustable combiningof the motions derived from the two crossheads which is progressively differentially varied with respect to the timing of the exhaust valves and the admission valves.

The present invention involves improvements especially in this field, and more particularly a new and useful mechanism for securing the differential adjustability with respect to the timing of the exhaust valves and the admission valves, whereby to obtain the desired delay of the release and compression events as the cutoff adjustment is progressively shortened. I

More specifically, the invention involves the provision, in a valve gear having separate takeoff connections from the combining lever mechanism to the admission and exhaust valves, of means for progressively altering the motion taken off from the exhaust combining levers differentially with respect to the motion taken off from the admission combining levers (with progressive change of the valve gear cut-off adjustment) by introducing into or combining with the said motion derived from the exhaust combining levers a variable component of motion derived from parts adjustably associated with the swinging links or equivalent parts of the valve gear.

Still more specifically, the invention involves, in a valve gear of this general character, the interposition of a secondary combining lever in the series of connections to the exhaust valve means, said secondary combining lever receiving a part of its motion from the primary exhaust combining lever, and part of its motion from an adjustable connection with the swinging link, and further the adjustment of the last named connection in coordination with and preferably by means of the main reversing device which reverses and' adjusts the cut-off of the valve gear. I

Still further, the invention contemplates the co-ordination of the above mentioned advantages with various advantages heretofore secured in mechanisms'such as disclosed in the above mentioned copending applications.

In addition, the invention involves a specific improvement in the mechanical movement for transmitting the variable motion from the main reversing mechanism to the adjustable actuating connection which is coupled with the aforesaid secondary combining lever.

How the foregoing objects and advantages are attained, together with such others as may be incident to the invention or as will ocur to those skilled in this art,-will be evident from the following description, taken together with the accompanying drawings, wherein:

Figure 1 is a fragmentary plan view of the running gear of a loco-motive, illustrating particularly the cylinders and valve chests, the associated reciprocating parts,-and the housing or box for ti valve .gearoi the present invention,

together with the operating connections to and from the valve gear box;

Figure 2 is a plan section through the valve gear box or housing of Figure l, to a larger scale, and showing the major essentials of the internal or working parts of the valve motion mechanism proper, in top plan, this View being taken. approximately on the line 22 of Figure 3;

Figure 3 is an irregular vertical longitudinal section through the valve gear box or casing of Figure 2, taken approximately on the line 33, and showing the chief elements of the valve gear which actuate the valves of the right-hand cylinder of the locomotive;

Figure 4 is a similar section taken approximately on the line 4-4 of Figure 2, and show ing the chief elements of the valve gear which actuate the valves of the left-hand cylinder of the locomotive;

Figure 5 is an irregular sectional view, similar to Figure 3, but showing the parts by which the cross-section or drive is taken from the left-hand part of the valve gear to the right hand swinging link (such parts being omitted from Figure 3 in order to avoid confusion);

Figure 6 is a similar sectional view, but related to Figure 4, showing the cross-connection for driving the left-hand oscillating link from the right-hand side of the valve gear (such parts being omitted from Figure 4 for the sake of clarity);

Figure 7 is a transverse vertical section through the valve gear box and internal mechanism, taken approximately on the line 'l-'l of Figure 2;

Figure 8 is a similar section taken approximately on the line 88 of Figure 2;

Figure 9 is a view chiefly in elevation, with certain parts in section, on a still larger scale, of a modified form of mechanical motion or interconnection which may be substituted for certain of the adjustment parts seen at the lefthand end of Figure 3;

Figure 10 is'a fragmentary section taken about on the line Ill-4!! of Figure 9;

Figure 11 is a section on the line H-H of Figure 9;

Figure 12 is a view similar to Figure 9 but showing the parts in a difierent position of adjustment;

Figure 13 is a sectional view similar to Figure 10, but taken on the line l3l3 of Figure 12; and

Figure 14 is a perspective view of three of the operating parts of the mechanism shown in Figures 9 to 13, the three parts being serially separated to illustrate how they can be assembled and disassembled.

Description of typical locomotive arrangement Referring now to Figure 1, it will be seen that the locomotive (the superstructure of which is not here shown) comprises main longitudinal framing 30, axles 31 (one of which is shown), driving wheels 32 (the forward pair of which is illustrated) cylinders 33, pistons diagrammatically indicated in dotted lines at 34, crank pins 35, piston rods 36, crossheads 31, crosshead guides 38, main rods 39 (which are only fragmentarily and diagrammatically indicated but which it will be understood couple the crossheads 31 to crank pins on drivers to the rear of those shown), valve chests 4|), steam delivery pipes 4 i saddle structure 42, steam exhaust outlets 43 for delivery to the nozzle (not shown), steam admission and exhaust valves, the stems or tappets of which are indicated at 445 and 44E, and cam boxes 45 containing the oscillatable inlet and exhaust cams (not shown) by which the valve operating arms 46S and 48E are actuated; all of which, for purposes of illustration, are similar to the corresponding parts of the locomotive illustrated in Figures 1 and 2 of the above mentioned Patent 2,138,053.

Also similar to the general arrangement of the application just mentioned, is the arrangement of the casing or box l5 for housing the major portion of the valve gear proper, said casing being mounted in any convenient manner, as by the base plate I6 which extends across from one side of the locomotive to the other and rests upon the main frame. The connection of the reach rod I! to the interior of the valve gear box is by means of a crank arm I8 fixed on the end of a rockshaft l9 extending into said box. Still further, in accordance with said general arrangement, the actuating connection from the two crossheads to the valve motion mechanism in the box, is by means of links 20, each coupled at its rearend by a pivotal connection 2| to a crosshead, and at its forward end by a pivotal connection 22 to the lower end of a lever 23, the upper end of which is fixed upon a rockshaft 24 extending into the valve gear box; and the steam and exhaust valve operating rockshafts 25S, 25E, extend outwardly from said box and fixedly carry arms or levers 26S, 26E, the upper ends of which are pivotally coupled to the rear ends of the actuating links 218, 21E, which at their forward ends are pivoted to the free ends of cam shaft crank arms 28S, 28E, which are fixed upon the independent steam and exhaust cam rockshafts 29S, 29E. The various rockshafts I9, 24, 25E and 258, may incorporate disconnectible couplings 41, 48, 49 and 50, located exteriorly of the box IE, for purposes of assembly and disassembly.

Further description of the general setting of the invention is not necessary here, nor is there need for illustration of the interior parts of the valve chests and cam boxes, since for a fuller understanding thereof reference may be had to said copending application 121,398 (now Patent 2,138,053).

Description of the valve gear proper Turning now'to Figures 2 to 8 inclusive, it will be noted that where the delivery and takeoff rockshafts pass into the inside of the box, the

designating numerals have the suflix or index.

letter R or L, for the right and: left sides of the mechanism, respectively. Insofar as practicable,

the details of the mechanism will now be described with reference to the portions of the valve gear which operate the valves at the right-hand of the right-hand cylinder, and to this end it pivotally carries at 54R. a combining lever structure which comprises a sleeve 55R. with integral admission and exhaust combining lever members 56R, 51R, the other connections to which will be described hereinafter. The. yoke member SIR furtherhas the function of transmittingmotion of the right-hand crosshead to the left-hand side of the mechanism, particularly to the swinging link thereof, and to this end it has a downwardly extending arm 5IR (see Figures 6 and 8) which has pivotally coupled thereto at 58R one end of a link 59R, the other end of which is pivoted at EUR to an arm SIR fixed on a short transverse rockshaft 62. The crossover shaft 62 fixedly carries another arm 63L, which in turn is pivoted at 54L to a'link 65L, the other end of which is pivoted at 66L to an arm 61L fixed on and extending upwardly from the inner trunnion member 68L of the left-hand arcuate swinging link 69L, which is thus oscillated in unison with the right-hand crosshead of the locomotive. v

Similarly, in order to actuate the right-hand swinging link, 69R (as seen from Figures 2, 5, i and 8),the left-hand primary oscillating yoke 5IL, which is actuated from the left-hand crosshead by means of the rockshaft 24L, carries (below its trunnion 52L) a downward extension 55L, which is pivotally coupled at 58L to the forward end of a link 59L, the rear end of which is pivoted at 60L to an arm GIL fixed upon a short transverse rockshaft l0. Said shaft crosses over to the right'of the longitudinal central vertical plane of the mechanism and there carries a second fixed arm 63R, which in turn is pivoted at MB to one end of a short link 55R, the other end of which is pivoted at 66R to a downwardly extending arm 61R which is fixed on the inner trunnion 6BR of the right-hand swinging link 69R, whereby said link is oscillated in unison with the left-hand crosshead of the locomotive engine.

By comparison of Figures 5 and 6, it will be seen that the crossover connections for transmitting the motion from the left-hand yoke 55 L to the right-hand swinging link 69R are placed lower in the casing than arethe corresponding connections transmitting the motion from the right-hand yoke SIR to the left-hand link 69L. This is not only for clearance purposes, but also in order that the respective transmission connections to the two swinging links shall be, respectively, below and above the oscillating centers thereof, since it is necessary that the swinging link on. one side he oscillated in like sense with the reciprocations of the piston at the opposite side of the locomotive and that the swinging link on the other side should be oscillated in opposite sense to the reciprocations of the opposite piston, in order that the valves for both cylinders will be timed for forward or reverse operation, respectively, when the link blocks in the two links are both moved by the reversing mechanism to their lower or upper positions, respectively. Otherwise, it would be necessary, in a two cylinder engine having the conventional 90 relative angular setting of the cranks, to employ a more cornplicated reversing mechanism, which would lower the link block in one swinging link simultaneously with the raising of the link block in the other swinging link. This principle is explained more fully in the first mentioned of the said copending applications, i. e., No. 58,504 (now Patent 2,136,405).

Having now explained the actuation of the right-hand oscillating yoke 5|R from the righthand crosshead, and the actuation of the righthand. swinging link 69R from the left-hand crosshead, there now follows an explanation of the combining of these motions, for the righthand side of the mechanism, and the actuation of the valves for the right-hand cylinder.

The radius rod HR is at its rear end pivoted at HR in a link block 12R which is slidable in the arcuate link 69R, and this adjustment (for alteration of cut-off, and for reversal of the engine) is effected by means of the lifting links 13R which are pivoted at HR to the radius rod HR and at 15R to the arm 76R which is fixed on the reversing shaft IS, the latter being actuated, as before stated, by means of an arm l8, outside the valve gear box, which is there coupled to the reach rod IT.

The forward end of the radius rod HR is pivoted at HR to the combining lever member 56R, with the result that the entire combining lever assembly 55R-5BR-51R as a unit receives a variable component of motion from the radius rod, according to the adjustment of the link block up and down in the swinging link 69R, which latter is oscillated in synchronism with the reciprocation of the left-hand piston of thelocomotive. The combining lever assembly, of course, also receives a fixed predetermined component of motion from the yoke MR which oscillates in unison with the reciprocation of the right-hand piston.

The take-off from the combining lever mechanism to the steam valve actuating rookshaft 258R is by means of a link 18R which has its rear end pivoted at 19R to the lower end of the admission combining lever member 56R and has its forward end pivoted at 80R to an arm HIR fixed upon the rockshaft 253R, which through the intermediation of the external lever 25S, link 21S, arm 28S and cam shaft 298, actuates the steam admission valves of the righthand cylinder.

Description of the major features of the present invention The take-01f from the exhaust combining lever member 51R to the exhaust valves is carried through a secondary combining lever, as will now be described. This take-01f is by means of a link 82R, pivoted to said combining lever member at 83R, and having connection to an arm I 84R fixed on rockshaft 25ER, through the intermediation of a secondary combining lever 85R,

which at one end has a pivotal'connection 86R to said link 82R and at an intermediate point has. a pivotal mounting 81R upon the said arm 84R. The lower end of the secondary combining lev'er 85R is pivoted at 88R to the forward end of a long rod or link 89R, the rear end of which is pivoted at 90R in a block SIR, slidable in a guideway or supplemental link member 92R which is fixed to and oscillates with the swinging link 69R.

The pivot center 90R, by the sliding of the block 9lR in the guideway 92R,-is adjustable from the extreme position shown in Figure 3 upwards to a point where said pivot center coincides with the center of oscillation of the trunnion 68R of the swinging link 69R, and this adjustment is effected in a predetermined relationship to the adjustment of the radius rods by the reversing mechanism. It may be effected by any suitable mechanism, one form being shown in Figures 2 and 3, and an alternative form being shown in Figures 9 to 14 inclusive.

Referring to Figures 2 and 3, the reversing shaft l9 carries a toothed sector 93, which meshes with a gear 94, fixed on stubshaft 95, and carrying an eccentric or crank 96.

Piv ted on 7 said crank is one end of a link 91, the other end of which is pivoted at 98 to an arm 99 fixed on a cross-shaft II), which extends from the right-hand to the left-hand side of the valve gear box. Considering the right-hand side of the mechanism, it will be seen that the shaft I09 fixedly carries another arm I DIR, which is pivoted at [02R to the upper end of a lifting link 193R, the lower end of which is pivoted by pin 99R to the slidable block 91R.

The parts of the valve motion mechanism are shown in mid-gear position. In this position the rear end pivot HR of the radius rod HR (see Figure 2) is on the center of oscillation of the swinging link 69R. (see Figure 3), so that no motion is transmitted from the link to the combining lever assembly 55R56R-51R. Said combining lever assembly is thus under these conditions oscillated solely by the primary transmission yoke 5IR which is oscillating in synchro nism with the reciprocation of the right-hand piston, and the admission valves are being thereby actuated for a timed opening and closing just equal to the desired preadmission. The exhaust valves, on the other hand, are receiving a relatively minor motion from the main combining lever 51R, since the motion derived therefrom, and transmitted through the link 82R to the secondary combining lever 85R and thence to lever MB, is substantially modified by the move= ment imparted to the other end of said secondary combining lever by the link 89R which is receiving motion from the guideway 92R which swings in unison with the swinging link 99R.

As illustrative of the effect of this motion taken from the swinging link 69R to the secondary combining lever 95R, reference may be made to Figures 3 and 4, which show the corresponding parts at the right and left sides of the mechanism. From Figure 3 it will be seen that the right-hand swinging link 69R. is inclined to one extreme of its oscillation, corresponding to the extreme forward position of the left-hand piston (dead center position of left-hand crank 35- see Figure 1), and the right-hand oscillating yoke 5lR stands substantially vertically, corresponding to the half-stroke position of the righthand piston (the right-hand crank 35 being adjacent the bottom of its cycle-as seen in Figure 1the locomotive illustrated being one in which the right-hand crank is the leading crank). From Figure 4 it will be seen that the left-hand swinging link 69L stands substantially in its vertical position, corresponding with the half-stroke position of the right-hand piston, and the left-hand oscillating yoke 5IL is inclined to one extreme of its oscillation, corresponding to the forwardmost position of the left-hand piston.

Thus, taking the two sides of the mechanism as illustrative of full-stroke and half-stroke positions for either side, it will be seen that the steam valve actuating levers 26S (Figs. 3 and 4) are at substantially differing angles. Yet the right and left exhaust valve actuating levers 26E (Figures 3 and 4) are both at substantially the same angle of inclination, which shows that as the pistons and cranks move through their cycles, the motion derived from the exhaust combining lever is to a large extent modified by means of the secondary combining lever which (in mid-gear position of the valve motion mechanism) receives a substantial component of motion from the swinging link.

It will now be seen (from Figure 3) that as the reversing lever l8 is -moved forward or backward from the mid-gear position shown, the'two radius rods HR, TIL will be moved downwards or upwards in the arcuate swinging links. This action, of course, causes forward or reverse operation of the engine, and introduces an adjustably variable component of motion from the links to the combining levers, for adjustment of the cut-ofi" and of the other valve events (admission, release and compression).

However, as the radius rod link blocks 12R, 12L, are moved progressively downward from the center of oscillation of the links (for forward operation) or progressively upward from the center of oscillation of the links (for reverse operation), the distance of the pivot centers 90R, 90L, of the supplemental rods or links 89R, 89L, from the centers of oscillation of the swinging links 69R, 69L, is progressively decreased. For the right-: hand side of the mechanism, this is accomplished (as seen in Figure 3) by the elements 93, 94, 96, 97, 98, 99, I00, IOIR, [92R and I93R.

96 to the lever 99 is on dead center when the valve motion mechanism is in mid-gear, it will,

readily be seen that movement of the toothed sector 93 either upwards (with forward motion of the reversing arm I8) or downwards (with rearward motion of the reversing arm I 8) will in either case produce a progressive reduction of the offset of pin 99R from the centerof oscillation of the swinging link 69R. In other words, a full throw of the reversing lever l3, moving the link block 12B of the radius rod HR from one extreme position of the link 69R to the opposite extreme position (i. e., from full-gear forward to full-gear reverse, or vice versa) is accompanied by a movement of the sliding block 9IR of the supplemental connecting link 89R. from its uppermost position in the guideway 92R, i. e., from the position where the pin 90R coincides with the axis of oscillation 68B of the link 69R, downwardly to the lowermost position in the guideway 92R and thence upwardly again to said center of oscillation.

Thus, when the link block of the radius rod HR is in either extreme position within the swinging link 69R, giving to the combining mechanism the maximum component of link motion, the supplemental combining lever (through the supplemental link 89R.) receives zero component of movement from the link motion; whereas, when the radius rod HR is in mid-gear and thus receives zero component of movement from the link motion, the supplemental rod 89R. receives its maximum movement from the link motion.

The adjustment of these parts, from the re-' versing shaft I9, is the same at the left-hand side as it is at the right-hand side which has just been described. This will be evident from Figures 2 and 4, which show the corresponding parts NHL, [92L, I93L, 99L, 9IL, 92L, etc., by which the supplemental left-hand rod 89L is adjusted in synchronism with the adjustment of the reversing mechanism. As all the remaining parts of the valve gear are duplicated at the two sides,

it will be unnecessary to describe in detail the structure at the left-hand side of the valve motion mechanism.

From the foregoing, it will now be evident that in the present embodiment of the invention (as in the case of the aforementioned Woodard Patent 2,136,405), the timing of the steam admission valves is determined by a combination of the following motions (considering, for example, the

valves at the right-hand side of the engine): first, a motion of uniform amplitudeand bearing a constant relation, as to direction, relative to the motion of the right-hand piston, which motion is derived from the right-hand crosshead and swinging link 69R. For the latest cut-off de-- sired the link block is placed in its extreme position in the link, thus imparting to the radius rod and thence to the combining lever assembly (from which the admission valves are driven) the maximum amount of motion which the link provides. This motion, in combination (by means of the admission combining lever member 58R) with the motion of the oscillating yoke |R produces the requisite timing of the admission valves for the latest cut-off desired. As the link block is moved progressively toward the center of the link, a smaller and smaller motion of the link is imparted to the radius rod and thence to the combining lever mechanism, the motion of the oscillating yoke member 5IR remaining always the same, with the result that the timing of the admission valves is progressively such as to give an earlier cut-oil. When the link block is moved to the central position, there is no motion imparted by the link to the radius rod and combining lever, and the timing of the admission valves cylinder producing a reversal of the engine.

The timing of the exhaust valves (still considering the right-hand part of the mechanism) is, in general, effected by the major parts of the mechanism as just described for the admission valves (including the oscillating yoke SIR, the

- swinging link 69R, the radius rod 'ilR, etc.), but the variably combined motion, taken off from the exhaust combining lever member 51B. is

modified (as the cut-off is progressively decreased), by a progressively increasing component of motion taken from the swinging link, byway of the supplemental rod 89R and the, secondary combining lever 85R, the action of which is to effect a differential variation of the timing.

of the exhaust valves as compared with the timing of the admission valves, so that as the out-01f is progressively made earlier and earlier, the re- I sion" events come much sooner than is desired. By the present mechanism there is secured a substantial improvementin the timing of the release and compression events at short cut-offs, even though the admission and exhaust valves are adjusted by means of an identical control memher, i. e., the reverse lever.

The particular means of co-ordinated adjustment between the reversing shaft 59 and the mechanism for modifying the motion taken off from the exhaust combining lever mechanism (i. e., the sector and gear arrangement 93, 94, and associated links and levers hereinbefore described with reference to Figures 2 and 3), which is similar to certain parts of the exhaust adjusting mechanism shown in said copending application No. 217,350, is herein employed, as a convenient means for securing the adjustment of the link motion delivered to the secondary combining lover. I have, however, evolved an alternative mechanical movement for effecting this adjustment, which will now be described with reference I to Figures 9 to 14 inclusive.

From Figure 9 it will be seen that the shaft i9 (adjustableby the lever l8) may have a system of bell cranks, linkages, etc., coupled to it in a manner to raise and lower the pin mm (which corresponds to the pins 12R and HEEL shown in Figures 3 and 4) for raising and lowering'the pivot centers 90R and 90L, through lift in, links 5MB, and HISL, to adjust the motion delivered to the secondary combining lever in accordance with the adjustment of the valve gear. This mechanism is mounted by and sup ported in a frame comprisinga base member Hi4 (see Figure 11) and right and left upright members N which may be secured to said base as by pins or bolts W ld. The base member may be mounted on any suitable support within the valve gear casing It: or directly on the floor thereof. The shaft 99' may be a supplemental shaft having its arm l8 coupled to an arm on the reversing shaft l9; or alternatively the shaft I9 and arm l8 may be considered to be identical with the reversing shaft i9 and reversing arm,

58, but relocated in the box to cooperate with the modified structure now being described.

Near the top of the side frame members H15, these parts have forward extensions 1855!. which are secured together by a through stud I06 having retaining nuts Hill threaded. thereon, said stud having an intermediate portion 193 of an enlarged diameter to serve as a pivot for the bell crank lFlQ. Toward the rear, the frame parts we have extensions lil5b which may be held in their relative positions by suitable collars Hi) fixed on the reversing shaft I5, on which shaft the bell crank IN is fixedas by a key 1 i2. The reversing arm I8 is, of course, also fixed on said shaft. The two bell cranks I09 and ill have downwardly extending arms I690. and i I la which are coupled together by links H3 and pivot pins lid, sothat, upon adjustment of the reversing shaft it by the reversing lever 18', the bell crank iii rocks with said shaft, and the bell crank M9, by means of the linkage H3, rocks in unison with the bell crank III (as best seen in Figure 12). 'The two bell cranks have their other arms i091) and lb extending generally horizontally toward each other (when the mechanism is in a position corresponding to mid position tothe reversing mechanism), the function of which will be hereinafter described.

Fixed upon the inner face of each side frame member I05, as by screws or studs H5, is an upstanding guide plate member IIG (best seen in Figures 9 and 14). Said guide plates have upright slots II'I cut therethrough (as seen in Figures 9, 11 and 14) serving as guideways for the vertically movable pin 98a, which corresponds in function to the pin 98 of the embodiment shown in Fig. 3. On the outer ends of pin 98a may be placed a pair of levers IOIa, having working slots IOIb (one of which is diagrammatically shown), which correspond in function to the levers IBIR. and IOIL of Fig. 2; any suitable fixed pivot or fulcrum point I000, being provided, in place of the shaft I00 seen in Figs. 2 and 3. To the pivots I020: may be coupled the upper ends of lifting links such as those shown at I03R and I03L in Figures 3 and 4, thus completing the connections to the supplemental adjustable rods 89R, 89L.

Below the slot 1, each guide plate IIIS has a U-shaped guideway or cam track III], the two legs of which respectively guide in a vertical path the positioning pins H9 which are fixed in and serve to prevent swinging displacement of the lower end of the lifting member I20 (see Figure 14) which carries the pin 98a.

The raising of the pin 98a in the guideways II? is accomplished through the intermediation of the member I20. At each face of the member I20 is another member I2I (one of which is shown in Figure 14) which is designed to effect the lowering of the pin 98a. Each of the two members I2I has at its upper end a hole I22 through which the pin 98a passes, with freedom for relative rocking. At an intermediate region, the member I2I has an arcuate slot I23 cut therethrough, through which pass the pins H9. Adjacent the bottom, the members I2I are fitted on to a pin I24, the ends of which ride in the U-shaped guideways H8.

It will now be seen that when the parts I20, I 2I and H6 (individually shown in Figure 14) are assembled together with their faces abutting-it being understood that the member I20 lies between two of the members I2I, and that the latter lie between two of the members .I IS--- the members I20 and I 2I may slide up and down as a unit between the members I I6, pin 98a being guided in slots II'I, pins H9 being guided in the two legs of the U-shaped slots II8, and pin I24 being movable alternatively in either of the legs of the U-shaped slots, since the members I2I may swing about the pin 98a, as a pivot.

The arms I09!) and lb of the bell cranks both underlie the bottom of member I 20 and partially overlie the pin I24, when the parts are in the position of Figure 9, i. e., when the valve gear is in mid-position, and at this time the pin 98a is at its lowermost position, and is there retained by the bell crank levers.

As the reversing shaft I9 is turned by its lever I8, clockwise to the position shown in Figure 12, corresponding to full-forward position of the valve gear, the following sequence of events occurs: the upper curved surface I25 of bell crank arm I09b commences to lift the member I20 and thus the pin 98a, and about the same time the protruding arcuate surface I26 of the bell crank lever IIIb pushes the pin I24 forwardly (as seen in Figure 9), whereupon said pin can ride up the forward leg of the U-slot IIB (Figure 12). In any given position of adjustment of the valve gear, in the forward range of valve gear adjustment, the pin 98a is held in a corresponding position of adjustment in the slots 1, by means of the bell crank arm I09b, the upper curved surface I25 of which bears against the bottom of the member I20, and the lower curved surface I21 of which bears against the top of the locking pin I24; the bell crank arm I I lb beingat this time entirely free of said parts, and thus ceasing to function.

Upon movement of the reversing gear into the reverse range, the bell crank III controls the vertical position of the pin-98a; the bell crank I09 being then non-functioning, so far as the positioning of said pinis concerned. 1

Thus, whether the reversing shaft is moved into its forward range or oppositely into its rearward range (for increase in valve gear cut-off adjustment), the pin 98a is in either case raised, which answers to the required condition, i. e., that the pins R and 90L of the supplemental connections to the secondary combining levers should be raised with increase in cut-off adjustment. In either case, the position of the pin 98a is positively fixed for any given positionof adjustment of the valve gear, since the particular bell crank which is functioning in the forward range or in the reverse range is positively interlocked with the connections to pin 98a, by means of that arm of the bell crank which fits between the member I20 and the pin I24.

From the foregoing detailed description of the mechanism, it will now be evident how I secure the various objects and advantages set forth in the earlier part of this specification, and particularly how the motion taken off from the primary combining lever mechanism is modified by means of a supplemental linkage and a secondary combining lever in order to avoid excessively early release and compression events of the exhaust valves at early cut-off adjustments of the admission valves.

I claim:

1. In locomotive valve gear, a primary combining lever actuated by a plurality of locomotive parts moving in different phase relation, a secondary combining lever receiving as a component of its motion the combined motion of said primary combining lever, a connectionto said secondary combining lever from one of the parts which actuated the primary combininglever, to supply another component of the motion of said secondary lever, and valve actuating connections coupled to each of said levers to take separate motions therefrom.

2. In locomotive valve gear, a primary combining lever actuated by a plurality oflocomotive parts moving in different phase relation, means for controllably varying at least-one of --the motions delivered to said mechanism, a secondary combining lever receiving as a component of its motion the combinedmotion of said primary com: bining lever, a connection to said secondary-com,- bining lever from one of the parts which actuate the primary combining lever, to supply another component of the motion of said secondary lever, and valveactuating connections coupled to each of said levers to take separate motions therefrom.

3. In locomotive valve gear, a primary combining lever actuated by a plurality of locomotive parts: moving in different phase relation, means for controllably varying at least one of the motions delivered to said mechanism, a secondary combining lever receiving as a component of its motion the combined motion of said primary combining lever, a connection to said secondary combining lever from one of the parts Which actuate the primary combining lever, to supply another component of the motion of said secondary lever, means for controllably varying the motion delivered by said connection to said secondary combining lever, and valve actuating connections coupled to each of said levers to take separate motions therefrom.

4. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the com bined motionfor timing one of said valve means, and secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timingthe other of said valve means.

5. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing one of said valve means, adjustable means for altering the component of motion received by said combining mechanism from one of said parts, and secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the other of said valve means.

6. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing one of said valve means, adjustable means for altering the component of motion received by said combining mechanism from one of said parts, secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the other of said valve means, and a second adjustable means for altering one of the component motions received by said secondary combining means.

7. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing one of said valve means, adjustable means for altering the component of motion received by said combining .mechanism from one of said parts, secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the other of said valve means, and a second adjustable means for altering one of the component motions received by said secondary combining means, and .a common control for both said adjustable means.

8. For alocomotive engine having cylinders,

pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering. the combined motion for timing one of said valve means, adjustable means for altering the component of motion received by said combining mechanism from one of said parts, secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the other of said valve means, and a second adjustable means for altering the component of motion received by said secondary combining means from the said moving part.

9. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gearcomprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing one of said valve means, adjustable means for altering the component of motion received by said combining mechanism from one of said parts, secondary combining means receiving the combined motion of said combining mechanism and a motion from the parts which actuate said mechanism. and delivering the resulting motion for timing the other of said valve means, and a second adjustable means for altering one of the component motions received by said secondary combining means, and a common control for both said adjustable means having control connections coupled to effect inverse alteration of the stated components of motion. l

10. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admis-= sion valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing the admission valve means, and secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the exhaust valve means.

'11. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing the admission valve means, adjustable means for altering the component of motion received by said combining mechanism from one of said parts whereby to alter the cut-off of the admission valve means with reference to thepiston stroke, and second.- ary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the exhaust valve means.

12. For a locomotive engine having cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, combining mechanism actuated by a plurality of said parts and delivering the combined motion for timing the admission valve means, adjustable means for altering the component of motion received by said combining mechanism from one of said parts whereby to alter the cut-off of the admission valve means with reference to the piston stroke, and secondary combining means receiving the combined motion of said combining mechanism and a motion from one of the parts which actuate said mechanism and delivering the resulting motion for timing the exhaust valve means, and a second adjustable means for altering one of the components of motion received by said secondary combining means whereby to efiect a delay of the release and compression events of the exhaust valve means as compared. with the timing of such events which would otherwise occur upon adjustment of the timing of the admission valve means for early cut-ofis.

13. For a locomotive engine having a pair of cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust Valve means, a valve gear comprising, for the valve means of each cylinder, a yoke member or the like oscillated in synchronism with the reciprocation of the piston in said cylinder, an arcuate swinging link or the like oscillated in synchronism with the reciprocation of the piston in the opposite cylinder, a combining lever or the like pivotally coupled to said yoke and having a connection adjustably coupling it to said link for variation and reversal of the motion delivered by said link to said lever, connections from said lever to the admission valve means for actuating the latter in timed relation to the reciprocation of the piston in said cylinder, a secondary combining lever or the like coupled to said first mentioned lever, an adjustable connection coupling said secondary lever to said link, and actuating connections from said secondary lever to said exhaust valve means for actuating the latter in timed relation to the reciprocation of the piston in said cylinder.

14. For a locomotive engine having a pair of cylinders, pistons and other moving parts actuated thereby, and for each cylinder relatively movable admission valve means and exhaust valve means, a valve gear comprising, for the valve means of each cylinder, a yoke member or the like oscillated in synchronism with the reciprocation of the piston in said cylinder, an arcuate swinging link or the like oscillated in synchronism with the reciprocation of the piston in the opposite cylinder, a combining lever or the like pivotally coupled to said yoke and having a connection adjustably coupling it to said link for variation and reversal of the motion delivered by said link to said lever, connections from said lever to the admission valve means for actuating the latter in timed relation to the reciprocation of the piston in said cylinder, a secondary combining lever or the like coupled to said first mentioned lever, an adjustable connection coupling said secondary lever to said link, actuating connections from said secondary lever to said exhaust valve means for actuating the latter in timed relation to the reciprocation of the piston in said cylinder, and a control device coupled to both adjustable connections in such manner as to increase the motion'delivered from the link to the secondary combining lever upon decrease of the motion delivered from the link to the first mentioned combining lever.

15. In a locomotive engine or the like, having at each side a cylinder, piston and other moving parts, and admission valve means and separately movable exhaust valve means for each cylinder,

a valve gear comprising an oscillating yoke or transmission lever at each side, said yokes being actuated in unison respectively with parts of said therefrom, for the combining lever assembly at each side a radius rod coupled thereto and slidably mounted in the link for that side and movable in the link on either side of the latters center of oscillation whereby each combining lever assembly may receive a variable and reversible component of motion from the corresponding link, a take-off connection from the combining lever assembly at each side and coupled to the admission valve means at that side for timing the same with relation to the reciprocation of the corresponding piston, a secondary combining lever at each side having a take-ofi connection from the respective combining lever assembly and having a second actuating means adjustably associated with the corresponding link, saidadjustable actuating connection being movable toward and away from the links center of oscillation at one side only of said center whereby the motion of said secondary combining lever is differentially variable with relation to themotion of the associated combining lever assembly, and operating connections from said secondary combining lever to the exhaust valve means of the corresponding cylinder for the timing of the same with relation to the reciprocation of the piston therein.

16. In a locomotive engine or the like, having at each side a cylinder, piston and other moving parts, and admission valve means and separately movable exhaust valve means for each cylinder, a valve gear comprising an oscillating yoke or transmission lever at each side, said yokes being actuated in unison respectively with parts of said engine moving in different phase relation, a pair of arcuate swinging links, one for each side, a crossover connection for oscillating the link of one side from and in like sense with the yoke at the other side, a crossover connection for oscillating the other link from and in opposite sense to the other yoke, a combining lever assembly pivotally mounted on each yoke to receive motion therefrom, for the combining lever assembly at each side a radius rod coupled thereto and slidably mounted in the link for that side and movable in the link on either side of the latters center of oscillation whereby each combining lever assembly may receive a variable and reversible component of motion from the corresponding link, a take-01f connection from the combining lever assembly at each side and coupled to the admission valve means at that side for timing the same with relation to the reciprocation of the corresponding piston, a secondary combining lever at each side having a take-01f connection from the respective combining lever assembly and having a second actuating means adjustably associated with the corresponding link,said adjustable actu- QfiIl'gCOIlllGCtlOIlbeing movable toward and away from-thelinks'center of oscillation at'one side only of said lcenter 'whereby the motion of said secondary combining .lever is differentially variable with relation to themo'tion of theassociated combining lever assembly, operating connections from said secondary combining lever to the exhaust valve. means of the corresponding cylinder for the timing of the same with relation to the IOJreciprocation of the piston therein, and adjusting mechanism coupled ta said radius rods for moving them together toward one end or the other-of said swinginglinks for forward and reverse operation respectively.

17.- InJa locomotive engine or the like, having at each side a cylinder, piston and other moving I parts, and admission valve means and separately movable exhaust valve means for each cylinder, a' valve. gear comprising an oscillating yoke or transmission lever at each side, said yokes being actuated in unison respectively with parts of said engine moving in difierent phase relation, a pair of arcuate swinging links, one for each side, a crossoverconnection for oscillating the link zs of one side from and in like sense with the yoke at the other sideya crossover connection for oscillating the other link from and in opposite sense to the other yoke, a combining lever assembly pivotally mounted on each yoke to receive motion therefrom, for the combining lever assembly at each side a radius rod coupled thereto and slidably mounted in the link for that side and movable in the link on either side of the latters center of oscillation whereby each com Dining lever assembly may receive a variable and reversible component of motion from the corresponding link, and take-off connection from the combining lever assembly at each side and coupled to the admission valve means at that Q side for timing the same with relation to the reciprocation of the corresponding piston, a secondary combining lever at each side having a take-off connection from the respective combining lever assembly and having a second actuating means adjustably associated with the corresponding link, said adjustable actuating connection being movable toward and away from the links center of oscillation at one side only of said center whereby the motion of said secondary combining lever is differentially variable with relation to the motion of the associated combining lever assembly, and operating connections from said secondary combining lever to the exhaust valve means of the corresponding cylinder for the timing'of the same with relation to the reciprocation of the piston therein, and adjusting mechanism coupled to said radius rods for moving them together toward one end or the other of said swinging links for forward and re- 50 verse operation respectively, and coupled to said adjustable actuating connections for said secondary combining levers for moving said connections toward the centers of oscillation of the links simultaneously with movement of said radius 65 rods in either direction away from said centers of oscillation.

18. In a locomotive engine or the like, having at each side a cylinder, piston and other moving parts, and admission valve means and separate- 70 ly movable exhaust valve means for each cylinder, a valve gear comprising an oscillating yoke or transmission lever at each side, said yokes being actuated in unison respectively with parts of said engine moving in different phase relation, a

15 pair of arcuate swinging links, one for each side,

a crossoverconnection for oscillating the link of one side from and in iike sense with the yoke at the-other side, a crossover connection-for oscillating the other link-from and in opposite sense to the other yoke, a combining lever assembly pivotally mounted on each yoke to receive motion therefrom, for the combining lever assembly at each-side a radius rod coupledthereto and slidably mounted in the linkfor that side and movable in the link on'eith'er' side of th61at'tefS-1 rl center of oscillation whereby each combining lever assembly may receive a variable and re-- versible component of motion from the corresponding link, a take-off connection from the combining lever: assembly at each side and couv15-5 ple'cl to the admission valvemeans at that side for timing the same with relation to the reciprocation of the corresponding piston, a secondary combining lev'erat' 'each side having a takeoff connection from the respective combining links center of oscillation at one side only of said 25 center whereby the motion' of said secondary combining lever is =-differentially variable with relation to the =motion'o-f. the associated combining lever assembly, and operating connections from said secondary combining lever to the ex- 36 haust valve means of the corresponding cylinder for the timing of the same with relation to the reciprocation of the piston therein, and adjusting mechanism coupled to said radius rods for moving them together toward one end or the 3 other of said swinging links for forward and reverse operation respectively, and coupled to said adjustable actuating connections for said secondary combining levers for moving said connections toward the centers of oscillation of the links 40 simultaneously with movement of said radius rods in either direction away from said centers of oscillation, said adjustable mechanism includ ing a reversing shaft rockable into a forward and a reverse range from a mid-gear position, as levers and lifting links coupling said shaft to said radius rods, a pair of lifting levers oppositely actuated by said shaft, a lifting pin adapted to be coupled to the said ad ustable actuating connections for said secondary combining levers, and so means alternatively coupling one of said lifting levers to said lifting pin upon rocking of said reversing shaft in the forward or the reverse range respectively.

19. For adjustable valve gear or the like, a link 55 lifting member, a guideway in which said member is adapted to reciprocate, a pair of shafts, lever arms on said shafts extending toward each other, actuating means for rocking one of said shafts and the lever which is fixed thereon through a forward and a reverse range of adjustment, an interconnection adapted to rock the other lever about the axis of its shaft in opposition to the rocking of said first mentioned lever, and actuating means coupled to said link lifting member and adapted to cooperate alternatively with one or the other of said lever arms to be moved thereby, respectively, upon rocking of said actuable shaft in the reverse or the forward range respectively.

20. For adjustable valve gear or the like, a link lifting member. a guideway in which said member is adapted to reciprocate, a pair of shafts, lever arms on said shafts extending toward each other, actuating means for rocking one of said shafts 

